Board logo

Help! Running problem on '893 blade engine
idl1975 - 9/2/09 at 08:34 AM

Wondering if anyone with experience with '893 blades (or otherwise) can assist.

Took my Indy to work today, and it appears to be missing either fuel or spark under load. Down hills it will run properly on a very light or trailing throttle. Up hills or with any throttle applied, it stutters and backfires. Basically sounds like a "Max Power" VW beetle.

It doesn't cut out altogether, and the problem is not gear or rev dependent, i.e. it doesn't clear at any given revs. The engine was idling high on the choke this morning as well (normally goes up to 4k once it's been running for a bit - was 5k this morning). Doesn't appear to be going away after 20 miles. The choke isn't stuck on, as far as I can tell. It has 3/4 of a tank of 97 in it, so it's not short of petrol.

The car did a track day at Brands and drove home the weekend before last, and has been sat in the dry since. No problems at that time.

I'd appreciate pointers from anyone who can suggest what the problem might be/have experienced this before.

I'm wondering whether this might be the famous Honda 4 reg/rec failure, but never having experienced it personally I'm not sure. I vaguely remember hearing that this can give load dependent symptoms, but I could be making that up.

Could it be an issue with the fuel pump? It appeared to come on normally when I turned the ignition on this morning. The in-line filter appears to be fairly dry, but this could be normal for all I know, as I've not spent a lot of time watching it intently...

Any ideas?

[Edited on 9/2/09 by idl1975]


Mr Whippy - 9/2/09 at 08:41 AM

carb ice...?

linky


idl1975 - 9/2/09 at 08:47 AM

Well, it's a stock blade engine on the original airbox, and they don't ice that severely. Plus idle behaviour is normal - hard starting and a reluctance to idle is invariably involved with icing...at least on all the bikes I've had that have done it. Plus it's been out in similar conditions before with no hint of a problem. So I don't think it's that.

quote:
Originally posted by Mr Whippy
carb ice...?

linky


nstrug - 9/2/09 at 10:40 AM

Fuel blockage? IIRC you don't have a pre-carb filter, just a pre-pump one. Although that wouldn't really explain the fast idle.

Nick


idl1975 - 9/2/09 at 10:48 AM

Yes, pre-pump only.

quote:
Originally posted by nstrug
Fuel blockage? IIRC you don't have a pre-carb filter, just a pre-pump one. Although that wouldn't really explain the fast idle.

Nick


Dangle_kt - 9/2/09 at 10:54 AM

water in the carbs? if so, drain float bowl and hope it isn't being drawn from the tank.


idl1975 - 9/2/09 at 10:56 AM

quote:
Originally posted by Dangle_kt
water in the carbs? if so, drain float bowl and hope it isn't being drawn from the tank.


Yeah, I've had something similar on a KTM. It hasn't been in the wet though.

I'll try to find the drain screws and give it a go...


mark chandler - 9/2/09 at 01:44 PM

Mines very sensitive to power, if the voltage drops then it splutters and will take no load, inconsistantly reving etc.

On the track day your lights would have been off, on the road were they all on? Try turning off and see if that resolves things, the bike alternator should be up to the job as blades have twin lights so its only an extra rear light so check earths etc.

Regards Mark


idl1975 - 9/2/09 at 02:41 PM

Thanks Mark, very interesting to hear. Actually had to have lights on on the track due to the bloody great blizzard...

However, it has done unusual electrical things before (indicators not working - seemed to be resolved by improving the wiring job), and the horn's now decided it's not working.

So it could well be something directlyo or indirectly causing a voltage drop... something like progressive reg/rec failure. I've ordered another reg/rec and will have to troubleshoot the other stuff this weekend.

Back on the bike for my commute then!


quote:
Originally posted by mark chandler
Mines very sensitive to power, if the voltage drops then it splutters and will take no load, inconsistantly reving etc.

On the track day your lights would have been off, on the road were they all on? Try turning off and see if that resolves things, the bike alternator should be up to the job as blades have twin lights so its only an extra rear light so check earths etc.

Regards Mark